Natural rubber, derived from the plant Hevea brasiliensis, is a core component of many consumer goods, including medical devices and products, such as latex gloves. The United States has a strong reliance on natural rubber, primarily because synthetic alternatives cannot match the high performance properties of natural rubber required for many applications and tend to be prohibitively expensive.
Over 90% of the Hevea-derived natural rubber imported by the United States originates in Indonesia, Malaysia and Thailand. Natural rubber sources in these countries are under intense threat from potential diseases and blights due to the genetic similarity of the rubber plants. Furthermore, the crop is limited by a restricted geographic area and labor-intensive harvesting methods. In addition, the Southeast Asian natural rubber crop contains many protein contaminants which are responsible for Type-I latex allergies, which are estimated to affect as many as 20 million Americans.
The high cost of importation to the United States, as well as the potential for the entire crop to be wiped out by disease and the ubiquity of latex allergies, make non-allergenic domestic natural rubber alternatives particularly attractive.
As an alternative to synthetic rubber sources, attention is being directed to the production of hydrocarbons in plants such as guayule (Parthenium argentatum). Guayule is a desert plant native to the southwestern United States and northern Mexico and which produces polymeric isoprene essentially identical to that made by Hevea rubber trees in Southeast Asia. Guayule plants store latex in tiny inclusions in the bark, making harvest of the outer fibrous layers of the plant, desirable. Guayule normally yields one half ton to one ton of rubber per acre in cultivation and is ready for harvest and processing after only two years.
Therefore, a need exists for a cost-effective, efficient, and environmentally friendly, high-yield method of extracting and fractionating biopolymers, such as rubber, from plant materials, such as guayule.